Switching apparatus are broadly used in many fields, such as emergency power supply. In case of a sudden power supply failure, typically a switching apparatus is activated to transfer the power line from normal power source to a replacement power source, such as a stand-alone generator. Most of the switching apparatus can be operated in two modes, i.e. automatically and manually, to accomplish said transferring motion.
Referring to FIG. 9 to FIG. 11, a conventional switching apparatus used in ATSE is shown. FIG. 9 is a top view of the conventional switching apparatus in manual mode, and FIGS. 10, 11 show a schematic cross sectional view of the conventional switching apparatus in automatic mode and manual mode respectively.
The conventional switching apparatus 1 has a frame 10, a handle 11, a clutch gear 12 driven by a motor via main gear (not shown), and a switch gear 13. The frame 10 has a circular notch 14 in its operating surface, and a support shaft 15, around which the handle can rotate to be lifted up.
In automatic mode, as shown in the FIG. 10, the handle 11 is in a lower position. The motor drives the main gear via clutch gear 12 to rotate, according to automatic operation signal received. Then the main gear drives the switch gear 13 to complete the motion of transferring a switching component to another position, and at same time the handle is driven to rotate too to provide corresponding position indication. Usually the handle 11 has a mark, which in combination with the marks on the operating surface of the frame 10, can indicate the amount of the rotation. For example, there are three marks on the operating surface of the frame 10, denoting an “OFF” position, a “N-ON” position and a “R-ON” position.
In manual mode, the handle 11 is lifted up, as shown in FIG. 11. A manipulator can rotate the handle 11, and the force applied by the manipulator then is transmitted to the switch gear 13. Like in automatic mode, the rotation angle is shown by means of the marks on the handle 11 and operating surface, and so the transferring process, such as transferring a power line to normal power source or to a replacement source, can be fulfilled properly.
However, in prior art, the handle 11 is coupled to the clutch gear 12 even when operated in manual mode. As the motor is connected to the clutch gear 12, additional force is needed to rotate the motor. Even when the power supply to the motor is cut off, the force required is quite large. But in the prior art assistant handle is a separate component and prone to loss. Besides this disadvantage, the prior art has a more serious drawback. In manual mode, due to possible misoperation, the motor may still have power supply and even receive false operation order, and the manual operation probably leads to damage of the motor and other safety problems.